title: Lack of viral selection in human immunodeficiency virus type 1 mother-to-child transmission with primary infection during late pregnancy and/or breastfeeding.
abstract: Mother-to-child transmission (MTCT) of human immunodeficiency virus type 1 (HIV-1) as described for women with an established infection is, in most cases, associated with the transmission of few maternal variants. This study analysed virus variability in four cases of maternal primary infection occurring during pregnancy and/or breastfeeding. Estimated time of seroconversion was at 4 months of pregnancy for one woman (early seroconversion) and during the last months of pregnancy and/or breastfeeding for the remaining three (late seroconversion). The C2V3 envelope region was analysed in samples of mother-child pairs by molecular cloning and sequencing. Comparisons of nucleotide and amino acid sequences as well as phylogenetic analysis were performed. The results showed low variability in the virus population of both mother and child. Maximum-likelihood analysis showed that, in the early pregnancy seroconversion case, a minor viral variant with further evolution in the child was transmitted, which could indicate a selection event in MTCT or a stochastic event, whereas in the late seroconversion cases, the mother's and child's sequences were intermingled, which is compatible with the transmission of multiple viral variants from the mother's major population. These results could be explained by the less pronounced selective pressure exerted by the immune system in the early stages of the mother's infection, which could play a role in MTCT of HIV-1.
authors.affiliation: National Reference Center for AIDS, Department of Microbiology, University of Buenos Aires School of Medicine, Buenos Aires, Argentina.
authors.forename: Ana
authors.initials: A
authors.lastname: Ceballos
authors.affiliation: National Reference Center for AIDS, Department of Microbiology, University of Buenos Aires School of Medicine, Buenos Aires, Argentina.
authors.forename: Guadalupe
authors.initials: G
authors.lastname: Andreani
authors.affiliation: Viral Evolution and Transmission Unit, DIBIT - San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Ripamonti
authors.affiliation: National Reference Center for AIDS, Department of Microbiology, University of Buenos Aires School of Medicine, Buenos Aires, Argentina.
authors.forename: Dario
authors.initials: D
authors.lastname: Dilernia
authors.affiliation: National Reference Center for AIDS, Department of Microbiology, University of Buenos Aires School of Medicine, Buenos Aires, Argentina.
authors.forename: Ramiro
authors.initials: R
authors.lastname: Mendez
authors.affiliation: National Reference Center for AIDS, Department of Microbiology, University of Buenos Aires School of Medicine, Buenos Aires, Argentina.
authors.forename: Roberto D
authors.initials: RD
authors.lastname: Rabinovich
authors.affiliation: Hospital Juan Fernández, Buenos Aires, Argentina.
authors.forename: Patricia Coll
authors.initials: PC
authors.lastname: Cárdenas
authors.affiliation: Hospital Juan Fernández, Buenos Aires, Argentina.
authors.forename: Carlos
authors.initials: C
authors.lastname: Zala
authors.affiliation: Hospital Juan Fernández, Buenos Aires, Argentina.
authors.forename: Pedro
authors.initials: P
authors.lastname: Cahn
authors.affiliation: Viral Evolution and Transmission Unit, DIBIT - San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Scarlatti
authors.affiliation: National Reference Center for AIDS, Department of Microbiology, University of Buenos Aires School of Medicine, Buenos Aires, Argentina.
authors.forename: Liliana Martínez
authors.initials: LM
authors.lastname: Peralta
mesh_terms: D000595:Amino Acid Sequence; D001942:Breast Feeding / Q000009:adverse effects*; D017931:DNA Primers; D005260:Female; D015658:HIV Infections / Q000635:transmission*; D015497:HIV-1 / Q000145:classification / Q000235:genetics* / Q000472:pathogenicity; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical; D008895:Milk, Human / Q000821:virology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D011247:Pregnancy; D011248:Pregnancy Complications / Q000821:virology*; D012641:Selection, Genetic; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014759:Viral Envelope Proteins / Q000235:genetics
chemical_list: D017931:DNA Primers; D014759:Viral Envelope Proteins